What material can I use for fake frosting?

Asked by raum (13208) November 8th, 2023 from iPhone

I need to make a cake prop for a theatrical production of Matilda. There’s a scene where one of the characters scarfs a giant chocolate cake.

The usual approach is to have slices of cake that squishes into the table or tray below to produce the illusion of disappearing cake.

I’m planning on making the cake out of high density foam that you’d find in your furniture cushions.

Though for the frosting part, what material could I use that looks like frosting, but is also squishable? Like spackle, but bendy.

Needs to be something I can buy locally and not have to special order! (Rules out stuff like polyurethane liquid mold rubber.)